Bump mapping is a texture-based rendering approach for simulating surface details to make its illumination results have three-dimensional effects. The bumpy properties of an object are determined by height maps. But i...Bump mapping is a texture-based rendering approach for simulating surface details to make its illumination results have three-dimensional effects. The bumpy properties of an object are determined by height maps. But in the process of generating height maps, a problem arises, i.e. to get a correct value of the pixel height, empirical data should be calculated repeatedly, which proves very complicated, and meanwhile the realistic rendering effect is reduced, because the bumpy property is exaggerated in the height map. Therefore, in this paper, we present a method for describing the details of the bumpy texture, where a new concept ＂bumpy map＂ is introduced to replace the height map. Experimental results demonstrate that the bumpy details produced by the ＂bumpy map＂ are more consistent with the original bumpy texture than by the method of height map.展开更多
In this paper, a facial animation system is proposed for capturing bothgeometrical information and illumination changes of surface details, called expression details, fromvideo clips simultaneously, and the captured d...In this paper, a facial animation system is proposed for capturing bothgeometrical information and illumination changes of surface details, called expression details, fromvideo clips simultaneously, and the captured data can be widely applied to different 2D face imagesand 3D face models. While tracking the geometric data, we record the expression details by ratioimages. For 2D facial animation synthesis, these ratio images are used to generate dynamic textures.Because a ratio image is obtained via dividing colors of an expressive face by those of a neutralface, pixels with ratio value smaller than one are where a wrinkle or crease appears. Therefore, thegradients of the ratio value at each pixel in ratio images are regarded as changes of a facesurface, and original normals on the surface can be adjusted according to these gradients. Based onthis idea, we can convert the ratio images into a sequence of normal maps and then apply them toanimated 3D model rendering. With the expression detail mapping, the resulted facial animations aremore life-like and more expressive.展开更多
基金Supported partially by the National Natural Science Foundation of China (Grant Nos. 60533030, 60825203, 60572104)National High-Tech Re-search & Development Program of China (Grant No.2006AA01Z317)Science and Technology Development Program of Education Commission in Beijing (Grant No. KM200710005017)
文摘Bump mapping is a texture-based rendering approach for simulating surface details to make its illumination results have three-dimensional effects. The bumpy properties of an object are determined by height maps. But in the process of generating height maps, a problem arises, i.e. to get a correct value of the pixel height, empirical data should be calculated repeatedly, which proves very complicated, and meanwhile the realistic rendering effect is reduced, because the bumpy property is exaggerated in the height map. Therefore, in this paper, we present a method for describing the details of the bumpy texture, where a new concept ＂bumpy map＂ is introduced to replace the height map. Experimental results demonstrate that the bumpy details produced by the ＂bumpy map＂ are more consistent with the original bumpy texture than by the method of height map.
文摘In this paper, a facial animation system is proposed for capturing bothgeometrical information and illumination changes of surface details, called expression details, fromvideo clips simultaneously, and the captured data can be widely applied to different 2D face imagesand 3D face models. While tracking the geometric data, we record the expression details by ratioimages. For 2D facial animation synthesis, these ratio images are used to generate dynamic textures.Because a ratio image is obtained via dividing colors of an expressive face by those of a neutralface, pixels with ratio value smaller than one are where a wrinkle or crease appears. Therefore, thegradients of the ratio value at each pixel in ratio images are regarded as changes of a facesurface, and original normals on the surface can be adjusted according to these gradients. Based onthis idea, we can convert the ratio images into a sequence of normal maps and then apply them toanimated 3D model rendering. With the expression detail mapping, the resulted facial animations aremore life-like and more expressive.
